lang/pbasic: include errno.h for errno

errno must be accessed by a macro from errno.h.

PR:		281784
Approved by:	portmgr (build fix blanket), mikael

lang/pbasic/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	pbasic
 PORTVERSION=	2.1
-PORTREVISION=	1
+PORTREVISION=	2
 CATEGORIES=	lang
 MASTER_SITES=	ftp://ftp.berklix.org/pub/FreeBSD/ports/distfiles/ \
 		http://www.berklix.com/~jhs/ftp/distfiles/

lang/pbasic/files/patch-bas3.c

@@ -0,0 +1,18 @@
+--- bas3.c.orig
++++ bas3.c
+@@ -2,6 +2,7 @@
+  * BASIC by Phil Cockcroft
+  */
+ #include        "bas.h"
++#include        <errno.h>
+ 
+ /*
+  *      This file contains the numeric evaluation routines and some
+@@ -1513,7 +1514,6 @@
+  */
+ #define	MAX_SYS_ARGS	6
+ 
+-extern	int	errno;
+ #ifdef	__STDC__
+ extern	int	syscall(int, ...);
+ #else